Abstract
The nesting of the Fermi surfaces of an electron and a hole pocket separated by a nesting vector and the interaction between electrons gives rise to itinerant antiferromagnetism. The order can gradually be suppressed by mismatching the nesting and a quantum critical point is obtained as the Néel temperature tends to zero. If the vector is commensurate with the lattice (umklapp with ), pairs of electrons can be transferred between the pockets and a superconducting dome above the quantum critical point may arise. If the vector is not commensurate with the lattice, there are eight phases that need to be considered: commensurate and incommensurate spin and charge density waves and four superconductivity phases, two of them with a modulated order parameter of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) type. The renormalization group equations are studied and numerically integrated. The phase diagram is obtained as a function of the mismatch of the Fermi surfaces and the magnitude of .
- Received 31 March 2015
DOI:https://doi.org/10.1103/PhysRevB.92.045115
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